Oil pressure light on/ milky oil after rebuild

[first time rebuild]

You’d have to have a pint of condensation for oil to turn that color. Are you changing filters too? They catch a lot of stuff and in this case I’d use 2-3 oil filters to catch and clean the impurities in the crankcase. Why did the oil light come on? ‘Oil’ too thin? It didn’t come on the first time when most of the water mix was present.

However, a head gasket may be blown or the new head has a crack or the block may be cracked. Could be the wrong head gasket? I’ve never taken an engine into a shop for a new head so I don’t know what your instructions to them were. A compression test or a leak down test should be next. Good luck.

So i got my hands on a compression tester, i found 170-175 in cylinder 1,2, and 4...150 in cylinder 3. from what Ive read, that seems to be my issue. hears to hoping its just the gasket

 

[WuzzaCBXRider]

So i got my hands on a compression tester, i found 170-175 in cylinder 1,2, and 4...150 in cylinder 3. from what Ive read, that seems to be my issue. hears to hoping its just the gasket

Yeah a loss of 25 should be the culprit. Time to remove the head and take a look. Fingers crossed it’s just the gasket.

 

[60+ Busa Rider]

So i got my hands on a compression tester, i found 170-175 in cylinder 1,2, and 4...150 in cylinder 3. from what Ive read, that seems to be my issue. hears to hoping its just the gasket

Unless you’re experienced looking at failed head gaskets then just remove the head gasket and do not wipe off any evidence and take the gasket to a professional engine builder for them to look at it. If you want to try looking at it yourself then do not wipe off the gasket and look for any black combustion soot escaping past the cylinder fire ring. The fire ring should be black free all the way around. Pay attention to any areas between the head bolts especially areas where there are wide spacing between any two bolts, in other words any area where the head can lift or flex. Assuming the head was properly surfaced then use a straight edge (a good framing square will work) and a feeler gauge and check the head in the middle and close the both long ends and diagonally in an X fashion. Rule of thumb is anything less that .004 (4 thousandths) will work but should be the max, the flatter the better.

My explanation above only addresses the low compression on one cylinder and may or may not explain the coolant and oil mixing. Not all coolant mixing is caused by a compression leak. Concentrate on the fire rings and water ports. Good luck.

 

[BlueBacon]

So i got my hands on a compression tester, i found 170-175 in cylinder 1,2, and 4...150 in cylinder 3. from what Ive read, that seems to be my issue. hears to hoping its just the gasket

Be sure to give us pics of it apart! Good luck

 

[sixpack577]

I would put a torque wrench on the headbolts, to at least see if they were torqued to spec.
That still won't tell you if they were torqued in the correct sequence, which does matter, but it will let you know if they were not tight enough.

 

[first time rebuild]

You’d have to have a pint of condensation for oil to turn that color. Are you changing filters too? They catch a lot of stuff and in this case I’d use 2-3 oil filters to catch and clean the impurities in the crankcase. Why did the oil light come on? ‘Oil’ too thin? It didn’t come on the first time when most of the water mix was present.

However, a head gasket may be blown or the new head has a crack or the block may be cracked. Could be the wrong head gasket? I’ve never taken an engine into a shop for a new head so I don’t know what your instructions to them were. A compression test or a leak down test should be next. Good luck.

So i got my hands on a compression tester, i found 170-175 in cylinder 1,2, and 4...150 in cylinder 3. from what Ive read, that seems to be my issue. hears to hoping its just the gasket

Unless you’re experienced looking at failed head gaskets then just remove the head gasket and do not wipe off any evidence and take the gasket to a professional engine builder for them to look at it. If you want to try looking at it yourself then do not wipe off the gasket and look for any black combustion soot escaping past the cylinder fire ring. The fire ring should be black free all the way around. Pay attention to any areas between the head bolts especially areas where there are wide spacing between any two bolts, in other words any area where the head can lift or flex. Assuming the head was properly surfaced then use a straight edge (a good framing square will work) and a feeler gauge and check the head in the middle and close the both long ends and diagonally in an X fashion. Rule of thumb is anything less that .004 (4 thousandths) will work but should be the max, the flatter the better.

My explanation above only addresses the low compression on one cylinder and may or may not explain the coolant and oil mixing. Not all coolant mixing is caused by a compression leak. Concentrate on the fire rings and water ports. Good luck.

Thanks for the advice. This forum is incredibly useful!

 

[first time rebuild]

Be sure to give us pics of it apart! Good luck

I will definitely post some updates once i have the motor apart!